The utility and need for head restraints in vehicles is well established. Such head restraints are devices to limit the rearward angular displacement of the vehicle occupant's head relative to his torso line. In fact, the Federal Department of Transportation (DOT) has a standard for such restraints as applied to passenger cars--see 49 CFR Ch.V, Section 571.202. The purpose of such head restraints is to reduce the frequency and severity of neck injury in rear-end and other collisions. Drivers and occupants of later model passenger cars are certainly familiar with such head restraints since DOT regulations do require that head restraints be installed in all passenger cars. However, such DOT regulations do not apply to trucks, and to passenger cars built prior to the effective date of the regulation.
With respect to so-called factory installed head restraints, such restraints are an integral part of the seat assembly and vertically adjustable to conform to occupant's of varying size. To attempt to incorporate a head restraint in a seat which is already installed in a vehicle would, at the very best, be both extremely difficult and expensive. Thus, there exists a need for a head restraint system which can be easily installed in vehicles without modification to the existing seat structure.